iio:pressure: initial zpa2326 barometer support

[cascardo/linux.git] / drivers / iio / pressure / zpa2326_spi.c

diff --git a/drivers/iio/pressure/zpa2326_spi.c b/drivers/iio/pressure/zpa2326_spi.c
new file mode 100644 (file)
index 0000000..bd2c1c3
--- /dev/null
+++ b/drivers/iio/pressure/zpa2326_spi.c
@@ -0,0 +1,103 @@
+/*
+ * Murata ZPA2326 SPI pressure and temperature sensor driver
+ *
+ * Copyright (c) 2016 Parrot S.A.
+ *
+ * Author: Gregor Boirie <gregor.boirie@parrot.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/of_device.h>
+#include "zpa2326.h"
+
+/*
+ * read_flag_mask:
+ *   - address bit 7 must be set to request a register read operation
+ *   - address bit 6 must be set to request register address auto increment
+ */
+static const struct regmap_config zpa2326_regmap_spi_config = {
+       .reg_bits       = 8,
+       .val_bits       = 8,
+       .writeable_reg  = zpa2326_isreg_writeable,
+       .readable_reg   = zpa2326_isreg_readable,
+       .precious_reg   = zpa2326_isreg_precious,
+       .max_register   = ZPA2326_TEMP_OUT_H_REG,
+       .read_flag_mask = BIT(7) | BIT(6),
+       .cache_type     = REGCACHE_NONE,
+};
+
+static int zpa2326_probe_spi(struct spi_device *spi)
+{
+       struct regmap *regmap;
+       int            err;
+
+       regmap = devm_regmap_init_spi(spi, &zpa2326_regmap_spi_config);
+       if (IS_ERR(regmap)) {
+               dev_err(&spi->dev, "failed to init registers map");
+               return PTR_ERR(regmap);
+       }
+
+       /*
+        * Enforce SPI slave settings to prevent from DT misconfiguration.
+        *
+        * Clock is idle high. Sampling happens on trailing edge, i.e., rising
+        * edge. Maximum bus frequency is 1 MHz. Registers are 8 bits wide.
+        */
+       spi->mode = SPI_MODE_3;
+       spi->max_speed_hz = min(spi->max_speed_hz, 1000000U);
+       spi->bits_per_word = 8;
+       err = spi_setup(spi);
+       if (err < 0)
+               return err;
+
+       return zpa2326_probe(&spi->dev, spi_get_device_id(spi)->name,
+                            spi->irq, ZPA2326_DEVICE_ID, regmap);
+}
+
+static int zpa2326_remove_spi(struct spi_device *spi)
+{
+       zpa2326_remove(&spi->dev);
+
+       return 0;
+}
+
+static const struct spi_device_id zpa2326_spi_ids[] = {
+       { "zpa2326", 0 },
+       { },
+};
+MODULE_DEVICE_TABLE(spi, zpa2326_spi_ids);
+
+#if defined(CONFIG_OF)
+static const struct of_device_id zpa2326_spi_matches[] = {
+       { .compatible = "murata,zpa2326" },
+       { }
+};
+MODULE_DEVICE_TABLE(of, zpa2326_spi_matches);
+#endif
+
+static struct spi_driver zpa2326_spi_driver = {
+       .driver = {
+               .name           = "zpa2326-spi",
+               .of_match_table = of_match_ptr(zpa2326_spi_matches),
+               .pm             = ZPA2326_PM_OPS,
+       },
+       .probe    = zpa2326_probe_spi,
+       .remove   = zpa2326_remove_spi,
+       .id_table = zpa2326_spi_ids,
+};
+module_spi_driver(zpa2326_spi_driver);
+
+MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>");
+MODULE_DESCRIPTION("SPI driver for Murata ZPA2326 pressure sensor");
+MODULE_LICENSE("GPL v2");